A/D CONVERTER OF FEEDBACK PULSE WIDTH MODULATION SYSTEM AND MEASURING DEVICE

PROBLEM TO BE SOLVED: To provide an A/D converter of feedback pulse width modulation system which allows for simultaneous sampling in measuring devices including a multipoint balance, while achieving cost reduction by reducing the number of components even in an A/D converter of feedback pulse width modulation system.SOLUTION: An A/D converter of feedback pulse width modulation system includes a first resistor, a second resistor, a third resistor, an integrator, and a voltage detector. The first resistor has one end connected with the input terminal of its own device, and the other end connected with one end of the second resistor, one end of the third resistor and one iput terminal of the integrator. A pulse signal is connected with the other end of the second resistor, and the integrator has the other input terminal connected with a reference voltage and the output terminal connected with the input terminal of the voltage detector. The voltage detector has an output terminal connected with the output terminal of its own device and the other end of the third resistor, and outputs a voltage of low level when the input voltage is equal to or lower than a predetermined voltage level, otherwise outputs a voltage of high level. 【課題】多点式秤を含む測定器における同時サンプリングを可能とし、かつ帰還形パルス幅変調方式のＡ／Ｄ変換器のなかでも構成部品数を減らし、コストダウンを実現する帰還形パルス幅変調方式のＡ／Ｄ変換器及び測定装置を提供する。【解決手段】帰還形パルス幅変調方式のＡ／Ｄ変換器は、第１抵抗、第２抵抗、第３抵抗、積分器、電圧検出器を備え、第１抵抗一端は自器の入力端子に接続され他端が第２抵抗一端と第３抵抗一端と積分器の一方の入力端子とに接続され、第２抵抗他端にパルス信号が接続され、積分器の他方の入力端子は基準電圧に接続され出力端子が電圧検出器の入力端子に接続され、電圧検出器の出力端子は自器の出力端子と第３抵抗他端とに接続され、電圧検出器は入力電圧が所定の電圧値以下である場合にローレベルの電圧を出力し入力電圧が所定の電圧値より高い場合にハイレベルの電圧を出力する。【選択図】図２